Two distinct anti-allergic drugs, amlexanox and cromolyn, bind to the same kinds of calcium binding proteins, except calmodulin, in bovine lung extract.

In order to explore candidates for proteins required in exocytosis, we used two anti-allergic drugs, amlexanox and cromolyn, which inhibit IgE mediated degranulation of mast cells and basophils, as molecular probes in affinity chromatography. These two drugs chiefly bound to the same kinds of calcium binding proteins in bovine lung. These proteins were as follows: bovine calgranulin C homolog, an 8-kDa unknown protein, S-100L, calgranulin B, calcyphosine, and annexins I-V. The homologous affinity of the two drugs to these proteins is in accord with the similar anti-allergic property of both drugs. From these findings it is presumed that these drugs interact with these proteins and affect pharmacologically the degranulation.